Session: MON 37-82-Pheochromocytoma & Paraganglioma
Poster Board MON-64
Clinical case: A 60 year old woman with resistant hypertension & type 2 diabetes for 15 years without prior DKA, was admitted for sudden onset of painful loss of vision in the left eye. For presumed optic neuritis, IV methylprednisone 120 mg was begun in the ER and within 14 hours she developed DKA (glucose 592 mg/dl, anion gap 21, positive urine ketones & arterial pH 7.26, bicarbonate 10 mEq/L). She was successfully treated with fluids and iv insulin, (8-10 units/hr) in the MICU. While there, she had an acute episode of shortness of breath and atrial flutter for which she was cardioverted and begun on iv heparin and esmolol, followed by diltiazem, metoprolol and lovenox. A CT of the chest did not confirm the suspected pulmonary emboli but showed an unexpected 1.5 cm right adrenal mass and a questionable 4.5 cm left adrenal mass. She again developed DKA requiring iv insulin until the DKA resolved. The diagnosis of a pheochromocytoma was considered.
The cathecholamines were markedly elevated: 24 hour urinary metanephrine 5,808 pmol/L (nl,35-460), 24 hour urinary normetanephrine 3,490 pmol/L (nl,10-1050), plasma metanephrine 756 pg/ml (nl,0-62), plasma normetanephrine 1,692 pg/ml (nl, 0-145). An adrenal CT confirmed the small right nodule with low attenuation consistent with adenoma and defined a left 5.8x4.6 cm adrenal mass enhancing to 101 HU with a washout greater than 50%. The differential included a cystic pheochromocytoma or carcinoma. The patient also had mildly elevated serum calcium (10.6 mg/dl) and PTH (220 pg/ml) levels without evidence of an adenoma on sestemibi scan nor elevated calcitonins (< 2 pg/ml). Ret proto-oncogene was negative. Since treatment already included metoprolol (beta blocker) & diltiazem, phenoxybenzamine (alpha blocker) was added in preparation for surgery.
Conclusion: This case demonstrates the combined effects of acutely increased glucocorticoids with chronically elevated catacholamines of a pheochromocytoma in precipitating diabetic ketoacidosis. Despite altered glucose metabolism, pheochromocytoma or glucocorticoids are rarely associated with DKA.
Elevated epinephrine levels affect glucose tolerance via alpha 2-adrenergic inhibitory & beta 2-mediated stimulatory effects on insulin secretion [1-3]. Elevated norepinephrine also suppresses insulin secretion, increases plasma glucagon and ketone production but its effect is less profound. Both catecholamines increase lipolysis, hepatic gluconeogenesis and peripheral insulin resistance [2–4]. The acute addition of glucocorticoids in this case precipitated DKA possibly by further inhibiting insulin secretion and insulin’s action in preventing ketogenesis.
Nothing to Disclose: RSC, KG, MAB, AAG
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